Objective:
Compare factors within and among modern cropping systems that may impact soil microbial communities, plant-microbe interactions, and plant health and productivity.

Approach:
To assess the weed management legacy on subsequent crops, several agricultural parameters will be measured in glyphosate resistant (GR) and non-GR sweet corn isolines, grown in fields with a legacy of glyphosate use and in fields where glyphosate has not been used for the past three or more years. The field design will allow comparisons of the plant genotype in isolation from the legacy of the farming system management and the plant genotype by systems interactions. Plots will be 15’ wide by 30’ long. For treatments receiving glyphosate, the herbicide will be applied at 0.84 kg a.e. ha-1 in a 130 Lha-1 spray volume at a pressure of 138 kPa when soybean and maize are at the V4–V5 and V5–V6 growth stages, respectively. Plots not receiving glyphosate will be hand-weeded periodically during the growing season. In addition, a subsample of GR and non-GR isolines of sweet corn plants plots will be challenged or not challenged with Goss’s wilt (Clavibacter michiganensis subsp. nebraskensis). Soil and plant samples will be taken at different times throughout the growing season, and shipped to Beltsville, MD for nutrient and microbial analysis.